// SPDX-License-Identifier: GPL-2.0-only
/*
 * Record and handle CPU attributes.
 *
 * Copyright (C) 2014 ARM Ltd.
 */
#include <asm/arch_timer.h>
#include <asm/cache.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpufeature.h>
#include <asm/fpsimd.h>

#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/compat.h>
#include <linux/elf.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/personality.h>
#include <linux/preempt.h>
#include <linux/printk.h>
#include <linux/seq_file.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/delay.h>

unsigned int system_serial_low;
EXPORT_SYMBOL(system_serial_low);

unsigned int system_serial_high;
EXPORT_SYMBOL(system_serial_high);

/*
 * In case the boot CPU is hotpluggable, we record its initial state and
 * current state separately. Certain system registers may contain different
 * values depending on configuration at or after reset.
 */
DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
static struct cpuinfo_arm64 boot_cpu_data;

static const char *icache_policy_str[] = {
    [ICACHE_POLICY_VPIPT] = "VPIPT",
    [ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
    [ICACHE_POLICY_VIPT] = "VIPT",
    [ICACHE_POLICY_PIPT] = "PIPT",
};

unsigned long __icache_flags;

static const char *const hwcap_str[] = {
    [KERNEL_HWCAP_FP] = "fp",
    [KERNEL_HWCAP_ASIMD] = "asimd",
    [KERNEL_HWCAP_EVTSTRM] = "evtstrm",
    [KERNEL_HWCAP_AES] = "aes",
    [KERNEL_HWCAP_PMULL] = "pmull",
    [KERNEL_HWCAP_SHA1] = "sha1",
    [KERNEL_HWCAP_SHA2] = "sha2",
    [KERNEL_HWCAP_CRC32] = "crc32",
    [KERNEL_HWCAP_ATOMICS] = "atomics",
    [KERNEL_HWCAP_FPHP] = "fphp",
    [KERNEL_HWCAP_ASIMDHP] = "asimdhp",
    [KERNEL_HWCAP_CPUID] = "cpuid",
    [KERNEL_HWCAP_ASIMDRDM] = "asimdrdm",
    [KERNEL_HWCAP_JSCVT] = "jscvt",
    [KERNEL_HWCAP_FCMA] = "fcma",
    [KERNEL_HWCAP_LRCPC] = "lrcpc",
    [KERNEL_HWCAP_DCPOP] = "dcpop",
    [KERNEL_HWCAP_SHA3] = "sha3",
    [KERNEL_HWCAP_SM3] = "sm3",
    [KERNEL_HWCAP_SM4] = "sm4",
    [KERNEL_HWCAP_ASIMDDP] = "asimddp",
    [KERNEL_HWCAP_SHA512] = "sha512",
    [KERNEL_HWCAP_SVE] = "sve",
    [KERNEL_HWCAP_ASIMDFHM] = "asimdfhm",
    [KERNEL_HWCAP_DIT] = "dit",
    [KERNEL_HWCAP_USCAT] = "uscat",
    [KERNEL_HWCAP_ILRCPC] = "ilrcpc",
    [KERNEL_HWCAP_FLAGM] = "flagm",
    [KERNEL_HWCAP_SSBS] = "ssbs",
    [KERNEL_HWCAP_SB] = "sb",
    [KERNEL_HWCAP_PACA] = "paca",
    [KERNEL_HWCAP_PACG] = "pacg",
    [KERNEL_HWCAP_DCPODP] = "dcpodp",
    [KERNEL_HWCAP_SVE2] = "sve2",
    [KERNEL_HWCAP_SVEAES] = "sveaes",
    [KERNEL_HWCAP_SVEPMULL] = "svepmull",
    [KERNEL_HWCAP_SVEBITPERM] = "svebitperm",
    [KERNEL_HWCAP_SVESHA3] = "svesha3",
    [KERNEL_HWCAP_SVESM4] = "svesm4",
    [KERNEL_HWCAP_FLAGM2] = "flagm2",
    [KERNEL_HWCAP_FRINT] = "frint",
    [KERNEL_HWCAP_SVEI8MM] = "svei8mm",
    [KERNEL_HWCAP_SVEF32MM] = "svef32mm",
    [KERNEL_HWCAP_SVEF64MM] = "svef64mm",
    [KERNEL_HWCAP_SVEBF16] = "svebf16",
    [KERNEL_HWCAP_I8MM] = "i8mm",
    [KERNEL_HWCAP_BF16] = "bf16",
    [KERNEL_HWCAP_DGH] = "dgh",
    [KERNEL_HWCAP_RNG] = "rng",
    [KERNEL_HWCAP_BTI] = "bti",
    [KERNEL_HWCAP_MTE] = "mte",
    [KERNEL_HWCAP_ECV]	= "ecv",
    [KERNEL_HWCAP_AFP]	= "afp",
    [KERNEL_HWCAP_RPRES]  = "rpres",
};

#ifdef CONFIG_COMPAT
#define COMPAT_KERNEL_HWCAP(x) const_ilog2(COMPAT_HWCAP_##x)
static const char *const compat_hwcap_str[] = {
    [COMPAT_KERNEL_HWCAP(SWP)] = "swp",
    [COMPAT_KERNEL_HWCAP(HALF)] = "half",
    [COMPAT_KERNEL_HWCAP(THUMB)] = "thumb",
    [COMPAT_KERNEL_HWCAP(26BIT)] = NULL, /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(FAST_MULT)] = "fastmult",
    [COMPAT_KERNEL_HWCAP(FPA)] = NULL, /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(VFP)] = "vfp",
    [COMPAT_KERNEL_HWCAP(EDSP)] = "edsp",
    [COMPAT_KERNEL_HWCAP(JAVA)] = NULL,    /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(IWMMXT)] = NULL,  /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(CRUNCH)] = NULL,  /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(THUMBEE)] = NULL, /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(NEON)] = "neon",
    [COMPAT_KERNEL_HWCAP(VFPv3)] = "vfpv3",
    [COMPAT_KERNEL_HWCAP(VFPV3D16)] = NULL, /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(TLS)] = "tls",
    [COMPAT_KERNEL_HWCAP(VFPv4)] = "vfpv4",
    [COMPAT_KERNEL_HWCAP(IDIVA)] = "idiva",
    [COMPAT_KERNEL_HWCAP(IDIVT)] = "idivt",
    [COMPAT_KERNEL_HWCAP(VFPD32)] = NULL, /* Not possible on arm64 */
    [COMPAT_KERNEL_HWCAP(LPAE)] = "lpae",
    [COMPAT_KERNEL_HWCAP(EVTSTRM)] = "evtstrm",
};

#define COMPAT_KERNEL_HWCAP2(x) const_ilog2(COMPAT_HWCAP2_##x)
static const char *const compat_hwcap2_str[] = {
    [COMPAT_KERNEL_HWCAP2(AES)] = "aes",     [COMPAT_KERNEL_HWCAP2(PMULL)] = "pmull",
    [COMPAT_KERNEL_HWCAP2(SHA1)] = "sha1",   [COMPAT_KERNEL_HWCAP2(SHA2)] = "sha2",
    [COMPAT_KERNEL_HWCAP2(CRC32)] = "crc32",
};
#endif /* CONFIG_COMPAT */

static int c_show(struct seq_file *m, void *v)
{
    int i, j;
    bool compat = personality(current->personality) == PER_LINUX32;

    for_each_online_cpu(i)
    {
        struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
        u32 midr = cpuinfo->reg_midr;

        /*
         * glibc reads /proc/cpuinfo to determine the number of
         * online processors, looking for lines beginning with
         * "processor".  Give glibc what it expects.
         */
        seq_printf(m, "processor\t: %d\n", i);
        if (compat) {
            seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n", MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);
        }

        seq_printf(m, "BogoMIPS\t: %lu.%02lu\n", loops_per_jiffy / (500000UL / HZ),
                   loops_per_jiffy / (5000UL / HZ) % 0x64);

        /*
         * Dump out the common processor features in a single line.
         * Userspace should read the hwcaps with getauxval(AT_HWCAP)
         * rather than attempting to parse this, but there's a body of
         * software which does already (at least for 32-bit).
         */
        seq_puts(m, "Features\t:");
        if (compat) {
#ifdef CONFIG_COMPAT
            for (j = 0; j < ARRAY_SIZE(compat_hwcap_str); j++) {
                if (compat_elf_hwcap & (1 << j)) {
                    /*
                     * Warn once if any feature should not
                     * have been present on arm64 platform.
                     */
                    if (WARN_ON_ONCE(!compat_hwcap_str[j])) {
                        continue;
                    }

                    seq_printf(m, " %s", compat_hwcap_str[j]);
                }
            }

            for (j = 0; j < ARRAY_SIZE(compat_hwcap2_str); j++) {
                if (compat_elf_hwcap2 & (1 << j)) {
                    seq_printf(m, " %s", compat_hwcap2_str[j]);
                }
            }
#endif /* CONFIG_COMPAT */
        } else {
            for (j = 0; j < ARRAY_SIZE(hwcap_str); j++) {
                if (cpu_have_feature(j)) {
                    seq_printf(m, " %s", hwcap_str[j]);
                }
            }
        }
        seq_puts(m, "\n");

        seq_printf(m, "CPU implementer\t: 0x%02x\n", MIDR_IMPLEMENTOR(midr));
        seq_printf(m, "CPU architecture: 8\n");
        seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
        seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
        seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
    }

    return 0;
}

static void *c_start(struct seq_file *m, loff_t *pos)
{
    return *pos < 1 ? (void *)1 : NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
    ++*pos;
    return NULL;
}

static void c_stop(struct seq_file *m, void *v)
{
}

const struct seq_operations cpuinfo_op = {.start = c_start, .next = c_next, .stop = c_stop, .show = c_show};

static struct kobj_type cpuregs_kobj_type = {
    .sysfs_ops = &kobj_sysfs_ops,
};

/*
 * The ARM ARM uses the phrase "32-bit register" to describe a register
 * whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however
 * no statement is made as to whether the upper 32 bits will or will not
 * be made use of in future, and between ARM DDI 0487A.c and ARM DDI
 * 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit.
 *
 * Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit
 * registers, we expose them both as 64 bit values to cater for possible
 * future expansion without an ABI break.
 */
#define kobj_to_cpuinfo(kobj) container_of(kobj, struct cpuinfo_arm64, kobj)
#define CPUREGS_ATTR_RO(_name, _field)                                                                                 \
    static ssize_t _name##_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)                          \
    {                                                                                                                  \
        struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj);                                                            \
                                                                                                                       \
        if (info->reg_midr)                                                                                            \
            return sprintf(buf, "0x%016x\n", info->reg_##_field);                                                      \
        else                                                                                                           \
            return 0;                                                                                                  \
    }                                                                                                                  \
    static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name)

CPUREGS_ATTR_RO(midr_el1, midr);
CPUREGS_ATTR_RO(revidr_el1, revidr);

static struct attribute *cpuregs_id_attrs[] = {&cpuregs_attr_midr_el1.attr, &cpuregs_attr_revidr_el1.attr, NULL};

static const struct attribute_group cpuregs_attr_group = {.attrs = cpuregs_id_attrs, .name = "identification"};

static int cpuid_cpu_online(unsigned int cpu)
{
    int rc;
    struct device *dev;
    struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

    dev = get_cpu_device(cpu);
    if (!dev) {
        rc = -ENODEV;
        goto out;
    }
    rc = kobject_add(&info->kobj, &dev->kobj, "regs");
    if (rc) {
        goto out;
    }
    rc = sysfs_create_group(&info->kobj, &cpuregs_attr_group);
    if (rc) {
        kobject_del(&info->kobj);
    }
out:
    return rc;
}

static int cpuid_cpu_offline(unsigned int cpu)
{
    struct device *dev;
    struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

    dev = get_cpu_device(cpu);
    if (!dev) {
        return -ENODEV;
    }
    if (info->kobj.parent) {
        sysfs_remove_group(&info->kobj, &cpuregs_attr_group);
        kobject_del(&info->kobj);
    }

    return 0;
}

static int __init cpuinfo_regs_init(void)
{
    int cpu, ret;

    for_each_possible_cpu(cpu)
    {
        struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

        kobject_init(&info->kobj, &cpuregs_kobj_type);
    }

    ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online", cpuid_cpu_online, cpuid_cpu_offline);
    if (ret < 0) {
        pr_err("cpuinfo: failed to register hotplug callbacks.\n");
        return ret;
    }
    return 0;
}
device_initcall(cpuinfo_regs_init);

static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
{
    unsigned int cpu = smp_processor_id();
    u32 l1ip = CTR_L1IP(info->reg_ctr);

    switch (l1ip) {
        case ICACHE_POLICY_PIPT:
            break;
        case ICACHE_POLICY_VPIPT:
            set_bit(ICACHEF_VPIPT, &__icache_flags);
            break;
        case ICACHE_POLICY_RESERVED:
        case ICACHE_POLICY_VIPT:
            /* Assume aliasing */
            set_bit(ICACHEF_ALIASING, &__icache_flags);
            break;
    }

    pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
}

static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
{
    info->reg_cntfrq = arch_timer_get_cntfrq();
    /*
     * Use the effective value of the CTR_EL0 than the raw value
     * exposed by the CPU. CTR_EL0.IDC field value must be interpreted
     * with the CLIDR_EL1 fields to avoid triggering false warnings
     * when there is a mismatch across the CPUs. Keep track of the
     * effective value of the CTR_EL0 in our internal records for
     * acurate sanity check and feature enablement.
     */
    info->reg_ctr = read_cpuid_effective_cachetype();
    info->reg_dczid = read_cpuid(DCZID_EL0);
    info->reg_midr = read_cpuid_id();
    info->reg_revidr = read_cpuid(REVIDR_EL1);

    info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
    info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
    info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
    info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
    info->reg_id_aa64isar2 = read_cpuid(ID_AA64ISAR2_EL1);
    info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
    info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
    info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
    info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
    info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
    info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_EL1);

    /* Update the 32bit ID registers only if AArch32 is implemented */
    if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
        info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
        info->reg_id_dfr1 = read_cpuid(ID_DFR1_EL1);
        info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
        info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
        info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
        info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
        info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
        info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
        info->reg_id_isar6 = read_cpuid(ID_ISAR6_EL1);
        info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
        info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
        info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
        info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
        info->reg_id_mmfr4 = read_cpuid(ID_MMFR4_EL1);
        info->reg_id_mmfr5 = read_cpuid(ID_MMFR5_EL1);
        info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
        info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
        info->reg_id_pfr2 = read_cpuid(ID_PFR2_EL1);

        info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
        info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
        info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
    }

    if (IS_ENABLED(CONFIG_ARM64_SVE) && id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
        info->reg_zcr = read_zcr_features();
    }

    cpuinfo_detect_icache_policy(info);
}

void cpuinfo_store_cpu(void)
{
    struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
    __cpuinfo_store_cpu(info);
    update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
}

void __init cpuinfo_store_boot_cpu(void)
{
    struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
    __cpuinfo_store_cpu(info);

    boot_cpu_data = *info;
    init_cpu_features(&boot_cpu_data);
}
